Conventional connectors for connecting a printed circuit board with the conductors of a FPC or the like include connectors that incorporated fork contacts as depicted in FIGS. 8 and 9. This type of connector 1 is mounted on the surface 2a of a printed circuit board 2, and comprises a plurality of contacts 3, each provided with a connection terminal portion 3a which is connected through soldering to a wiring pattern 2b on the printed circuit board 2 and with resilient spring portions 3b and 3c which clamp the connection conductors 4a of the FPC through spring force; and an insulator element 5 which holds the row of contacts in place. When manufacturing the contacts 3, a punched form having the contact shape depicted in cross section in FIG. 9 is produced from a sheet material by stamping in order to reduce the amount of bending required. With this process, the cut edge of the punched form constitutes the contact portion 3d of the resilient spring portion 3b which comes into sliding contact with a connection conductor 4a of the FPC. In some cases, this may damage the surface of the connection conductor 4a, producing an unreliable connection. Further, material strength considerations make it difficult to thin the contact 3 retainer portions 5a and 5b of the insulator element 5; accordingly, the component is unsuitable to meet the current requirements for lower profiles, that is, a lower connector profile when mounted on a printed circuit board.
One more type of conventional connector includes a plate spring contact (termed a "reverse cantilever type") as depicted in FIGS. 10 and 11. This type of connector is widely employed owing to its cost advantages. The disposition of elements in this connector 11 for connecting a FPC 14 to a printed circuit board 12 is analogous to that in the fork contact type depicted in FIGS. 8 and 9. While the reverse cantilever contact 13 reduces the problem of damage to the connection conductors 4a associated with the fork contact 3, and is easily assembled within the insulator element 5, it has problems of its own as when the number of contacts is increased to meet current requirement for multi-way connections, it unavoidably causes increases in the sum of the forces applied to the FPC 14 by the resilient spring elements 13b. Such force may cause undesirable widening of the opening 16 provided to the insulator element 15 for insertion of the FPC 14, which may result in unreliable connection. It would be possible to prevent this by increasing the thickness of thin portions 15a and 15b of the insulator element 15, but this would render the component unsuitable as a connector to meet the lower profiles current requirements.
One additional type of conventional connector is the detachable cover type depicted in FIGS. 12 and 13, which is provided with a metal cover having a squared-off U-shaped transverse cross section. The connector body. 21 has a connection face 21a for effecting connection with the surface 22a of the printed circuit board 22, and outer contacts 23b, located at the side faces 21b adjacent to the connection face, for effecting connection with the FPC 24. A metal cover 25, which fits from the direction of the face 21c opposite the connection face 21a of the connector body 21, is provided with opposing side pieces 25a and 25b that clamp the connector body 21 and the FPC 24 together through spring force. With this structure, the reinforcing effect provided by the squared-off U-shaped cross section of the metal cover 25 reduces bending of the connector body 21 in the lengthwise direction. However, in order to accommodate FPC of various thicknesses, specifically, to provide consistent forcible contact as well as a clearly dissemble sensation associated with attachment and detachment of the cover regardless of the thickness of the board, it is necessary to ensure that the resilient spring pieces 23c and the metal cover side pieces 25a each have sufficient length. Accordingly, this structure is also unsuitable to meet the current need for low profiles.
It is therefore an object of the present invention to provide, in a device for connecting a flexible conductive line component to a printed circuit board, a connector for flexible conductive line components which overcomes the disadvantages of the aforementioned prior art connectors, and which affords reliable connections in a compact device.